A small car and a large truck have the same momentum. What can you say about the
ID: 1261093 • Letter: A
Question
A small car and a large truck have the same momentum. What can you say about their kinetic energies? a. The truck has more kinetic energy . b. The car has more kinetic energy. c. They have equal kinetic energies. (Questions 8 - 10) Shown at right is a frictionless roller coaster. The car is lifted slowly up the first hill (A to B) by the lift chain, reaching B with a negligible velocity (vB 0). The car then coasts freely from B to C to D, etc. 8. How does the car's mechanical energy at point B compare to its mechanical energy at A? a. EB EA 9. Hon does the car's mechanical energy at point D compare to its mechanical energy at C? a. ED EC 10. How does the car's kinetic energy at point D compare to its kinetic energy at point C? e. Without knowing the mass of the car, you can't compare them.Explanation / Answer
8 . using energy conservation
total mechanical energy is same at every point ,.
b. Eb = Ea
9 . using energy conservation
total mechanical energy is same at every point ,.
b. Ed = Ec
10.
using energy conservation ,
energy ar D = energy at C
Kd + mg(h/3) = kC + 0
Kd - Kc =mgh
so we can say kd > Kc
Ans (a)